This invention relates to a seat device for a vehicle such as a motorcar and the like, and more particulary to a reclining seat device for adjusting the angle of the seat back to a desired degree.
The reclining seat device is usually disposed in a position where the seat cushion is connected to the seat back and a device by which a driver or passenger can rotate and adjust the seat back at a suitable angle as he likes. Accordingly, when the seat back is adjusted and locked at a desired angular position, the reclining device must withstand a certain load given by the seat back per se with no unsteadiness.
There are some seat back inclining devices heretofore used, wherein serrations are formed on the outer circumference of the root end of a seat back arm attached to the seat back and clicks meshable with said serrations are also provided on a base plate, for the purpose of locking the seat back to the seat cushion. As this seat back inclining device resists the energy of about 75 kilogram-meters, the load problem may be left out of consideration in the usual condition of use. However, in case not only a seat belt is provided spanning the seat cushion at the upper portion of the seat back, but an air bag is also equipped on the back surface of the seat back, an excessively great energy, on collision acts forward on the seat back instantaneously through said seat belt and the air bag. Therefore, it is required that the lock structure should withstand the energy of the order of at least 500 to 1000 kilogram-meters.
Consequently, an object of the present invention is to provide an improved seat back inclining device in which the adjusting and setting of the seat back at a desired angle is easily and securely effected and the load withstanding performance is high in the locked condition of the seat back.
Another object of the present invention is to provide a seat back inclining device for use with the so-called two door type motorcar, in which getting on and off the rear seat is performed by opening a side door for the front seat and inclining forward the back of the front seat, wherein the forward inclining of the front seat back may be effected either from the front seat or from the rear seat.
A further object of the present invention is to provide a seat back inclining device including a rear lever for handling the front seat back which is easily operative and does not obstruct the passage even in the inclined state.
However, when the seat back is returned from the inclined position to the original set position, it has an inconvenience that the return to the original set position can not be performed automatically.
With due regard to the above inconveniences, yet another object of the present invention is to provide a seat back inclining device including memory means for automatically and instantly returning the seat back to the previously memorized standing position from the inclined position thereof.
A further object of the invention is to provide a reclining device easily operatable for a passenger at the rear seat and including memory means for automatically returning and locking the seat back to a set position after being inclined.
Briefly, the seat back inclining device according to the present invention includes a fixed seat cushion base provided with a horizontal or transverse shaft and a seat back arm supported upon said base so as to be rotatable around the transverse shaft. The seat back arm and the base are provided with serrations respectively which are normally meshed with each other. A forward release lever is pivotably supported at the horizontal shaft and includes means for releasing the engagement between said seat back arm and said base. When the release lever is turned clockwise around the horizontal shaft, the engagement between said seat back arm and said base is released, and then the seat back may be rotatable around the transverse shaft.
The release lever is provided with a return spring, and accordingly by adjusting the seat back at a suitable angle and letting off the release lever, the seat back may be set at a desired angle position.
The seat back inclining device according to the present invention may include a handling means for a passenger at the rear seat to incline the back of the front seat. Said handling means includes the back lever which is rotatably attached to said transverse shaft and is easily operatable by the passenger at the rear seat. Said back lever includes means engageable with to the front release lever, which, when turned clockwise, is engaged with to the front lever to turn the front lever clockwise, thus releasing the engagement between the seat back arm and the base.
Further the reclining seat device according to the present invention may include memory means typically formed in a substantially ring-shaped member rotatably and concentrically arranged around the transverse shaft, a cam portion being provided on the external circumference of the ringed member. When the angle of said seat back arm relative to said base becomes a fixed degree, another member associated with said cam portion may return the forward release lever, and then returns said seat back arm to a desired position.
Other objects and advantages of the invention will become apparent from the following descriptions taken in connection with the accompanying drawings.